Systems and methods for reducing corrosion in a reactor system using corrosion protection layers

ABSTRACT

Systems and methods for reducing or eliminating corrosion of components of a reactor system, including a supercritical water gasification system, are described. Corrosion protection layers may be configured to provide a physical barrier between component surfaces and subcritical fluid present in one or more subcritical zones during operation of the reactor system. The corrosion protection layers may include glass and silicon carbide, and may be positioned within the one or more subcritical zones to prevent the subcritical fluid from contacting component surfaces susceptible to corrosion from corrosive ions present in the subcritical fluid.

BACKGROUND

Supercritical water gasification generates hydrogen-rich synthesis gas by reacting a feedstock slurry with supercritical water. Supercritical water is water that is heated to very high temperatures (for example, above about 674 Kelvin) and under high pressures (for example, about 22 megapascals) such that the water is prevented from turning into steam. At this temperature, the water becomes very reactive and is capable of breaking down a slurry to generate the hydrogen-rich fuel. The fuel may be used for various purposes, such as powering an engine, producing electricity and generating heat. One advantage of supercritical water reactor systems is that they are capable of producing relatively clean hydrogen-based fuel from feedstocks that are considered waste, such as liquid biomass, or unclean fuel sources, including coal and other fossil fuels.

The efficiency and cost-effectiveness of supercritical water gasification is affected by the rapid corrosion of components, such as heaters and reactor vessels, particularly regions of the components that come into contact with water at high temperatures. Conventional techniques to manage corrosion involve the constant replacement of corroded parts, or constructing components from corrosive resistant materials, which can be expensive and largely ineffective. It will therefore be desirable to reduce corrosion in reactor systems, such as in supercritical water reactor systems, in a manner that minimizes the economic impact of corrosion through the use of inexpensive and easily replicable components.

SUMMARY

This disclosure is not limited to the particular systems, devices and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope.

As used in this document, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Nothing in this disclosure is to be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term “comprising” means “including, but not limited to.”

In an embodiment, a reactor system configured to reduce or eliminate corrosion thereof may comprise a system vessel comprising an inner surface, and having a subcritical zone. The subcritical zone may be configured to receive fluid at subcritical conditions. At least one corrosion protection layer comprising glass and silicon carbide may be positioned within the subcritical zone to provide a physical barrier that protects at least a portion of the inner surface from corrosion.

In an embodiment, a method for manufacturing a reactor system configured to reduce or eliminate corrosion thereof may comprise providing a system vessel and at least one corrosion protection layer. The system vessel may comprise an inner surface, and have a subcritical zone. The subcritical zone may be configured to receive fluid at subcritical conditions. The at least one corrosion protection layer may comprise glass and silicon carbide. The at least one corrosion protection layer may be positioned inside the system vessel within the subcritical zone to provide a physical barrier that protects at least a portion of the inner surface from corrosion.

In an embodiment, a method of manufacturing a corrosion protection layer of a reactor system using crystal encapsulation, may comprise providing a mold configured such that a corrosion protection layer generated within the mold substantially conforms to a size and shape of at least a portion of a system vessel of the reactor system such that the corrosion protection layer fits therein. Silicon carbide crystals and molten glass may be placed into the mold. The mold may be rotated until the molten glass hardens to form the corrosion protection layer within the mold. The corrosion protection layer may be removed from the mold.

In an embodiment, a method of manufacturing a corrosion protection layer of a reactor system using filament winding, may comprise providing a mold configured such that a corrosion protection layer generated through filament winding using the mold substantially conforms to a size and shape of at least a portion of a system vessel of the reactor system such that the corrosion protection layer fits therein. The mold may be rotated, and silicon carbide fibers may be applied under high tension to the rotating mold. Silicon carbide fibers may be impregnated with molten glass during application of the silicon carbide fibers to the rotating mold. The application of the silicon carbide fibers to the rotating mold may be stopped responsive to the corrosion protection layer substantially conforming to the size and shape of the at least a portion of the system vessel. The corrosion protection layer may be solidified and the mold removed from within the corrosion protection layer.

In an embodiment, a corrosion reduction method for a reactor system may comprise providing a reactor system having a system vessel, the system vessel comprising an inner surface, and having a subcritical zone configured to receive fluid at subcritical conditions. The method may further comprise providing at least one corrosion protection layer comprising glass and silicon carbide, and positioning the at least one corrosion protection layer within the subcritical zone to provide a physical barrier that protects at least a portion of the inner surface from corrosion by the fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an illustrative supercritical water system according to some embodiments.

FIGS. 2A and 2B depict different views of an illustrative supercritical water reactor system component comprising a corrosion protection layer according to some embodiments.

FIGS. 3A and 3B depict illustrative corrosion protection layers generated through encapsulation processes using different sizes of silicon carbide crystals.

FIG. 4 depicts a flow diagram for an illustrative corrosion reduction method for a supercritical water reactor system according to some embodiments.

FIG. 5 depicts a flow diagram for an illustrative method of providing a corrosion protection layer using a filament winding process according to some embodiments.

DETAILED DESCRIPTION

The terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope.

The present disclosure relates generally to systems and methods for reducing or eliminating corrosion in reactor systems. The reactor systems may include supercritical water reactor systems. In particular, embodiments provide a corrosion protection layer configured to provide a physical barrier against subcritical fluid in a reactor system. Subcritical fluid includes fluid at subcritical conditions or at a high temperature that is below the temperature for supercritical fluid. For instance, subcritical water may include water at about 600 Kelvin to about 647 Kelvin at a pressure of about 22 megapascals. In an embodiment, the corrosion protection layer include glass and silicon carbide. The systems and methods described herein may provide an effective and cost-efficient way to protect reactor system components, such as those in supercritical water reactor systems, from corrosion while presenting a minimal barrier to heat transfer and resisting chemical breakdown by the subcritical fluids in the reactor system.

Use of the corrosion protection layer, methods and systems described herein can result in a reduction or elimination of corrosion in a reactor or reactor system components relative to operation of the same or similar reactor or reactor system components without the described corrosion protection layer, methods and systems. The degree of corrosion can generally be reduced by any amount. For example, the degree of corrosion can be reduced by at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, and in an ideal situation, about 100% reduction (complete elimination of corrosion).

FIG. 1 depicts an illustrative supercritical water reactor system according to some embodiments. As shown in FIG. 1, a supercritical water reactor system 100 may include a feedstock inlet 130 for introducing a slurry 155 into the system. The slurry 155, for example, may include a high pressure slurry feed. The slurry 155 may include any type of matter capable of undergoing supercritical water gasification, including, without limitation, biomass fluids (for example, micro algae fluids, bioresidues, biowastes, or the like), slurries of coal and other fossil fuels, and oxidizable wastes. Accordingly, the supercritical water reactor system 100 may be configured to operate as any of various gasification systems, including, without limitation, a coal gasification system, a biomass gasification system, and a waste oxidation system. The slurry 155, along with air 150 and water 135, may be fed into a heater 105, such as a gas-fired heater. The slurry 155 may be heated in the heater 105. Certain gases, such as steam 140 and flue gas 145, may be exhausted from the heater, for instance, to maintain pressure. The slurry 155 may be fed into a reactor vessel 110.

Within the reactor vessel 110, the slurry 155 may be heated under pressure to become a supercritical fluid. The temperatures and pressures for generating a supercritical fluid will depend on the type of slurry 155, any fluids included therein, and the composition thereof (for example, the type and concentration of ions at different temperatures and pressures). In an embodiment, the slurry 155 may be heated to above about 647 Kelvin at a pressure above about 22 megapascals such that fluid within the slurry becomes a “supercritical fluid.” According to some embodiments, the slurry 155 may be heated to about 920 Kelvin at a pressure of about 25 megapascals within the reactor vessel 110. The slurry 155 under supercritical conditions includes corrosive ions such as the ions of various inorganic salts. The corrosive ions may be highly corrosive to the components of the supercritical water reactor system 100, such as the inside surface of the heater 105, the reactor vessel 110, and/or any pipes connecting the components together. In an embodiment, the fluid within the slurry 155 may include water.

The supercritical fluid may react with the components of the slurry 155 within the reactor vessel 110 to generate a reactor product 160. In an embodiment, the slurry 155 may include one or more catalysts configured to facilitate the reaction, such as chlorine, sulfate, nitrate, and phosphate. The reactor product 160 may move through one or more heat exchangers, such as a heat recovery heat exchanger 115 and a cool-down heat exchanger 125. A gas/liquid separator 120 may be provided to separate the reactor product 160 into the desired fuel gas product 165 and waste products 170, such as liquid effluent, ash and char. The fuel gas product 165 may include any fuel capable of being generated from the slurry 155 responsive to reacting with the supercritical fluid. Illustrative fuel gas products 165 include, but are not limited to, hydrogen-rich fuels, such as H₂ and/or CH₄.

During the supercritical water gasification process, the slurry 155 may be heated to various temperatures under different pressures within the supercritical water reactor system 100. In addition to supercritical conditions, the slurry 155 may be in a subcritical condition, wherein the fluid within the slurry 155 is at a high temperature, under pressure, that is below the supercritical temperature. In an embodiment wherein the fluid within the slurry 155 includes water, subcritical water may have a temperature of about 550 Kelvin, 570 Kelvin, 600 Kelvin, about 610 Kelvin, about 620 Kelvin, about 630 Kelvin, about 647 Kelvin, or in a range between any of these values (including endpoints). In an embodiment wherein the fluid within the slurry 155 includes water, the pressure of the fluid at the subcritical temperature may be about 20 megapascals, about 22 megapascals, about 25 megapascals, or in a range between any of these values (including endpoints). The slurry 155 under subcritical conditions typically includes corrosive ions that are highly corrosive to the components of the supercritical water reactor system 100. Non-limiting examples of corrosive ions include various ions of chlorine, sulfur (for example, sulfer dioxide), phosphorous, or the like.

The supercritical water reactor system 100 may have one or more subcritical zones where the slurry 155 is located during at least a portion of the supercritical water gasification process. Non-limiting examples of subcritical zones include, without limitation, the pre-heat 175 and cool-down 180 zones of the reactor vessel 110. According to some embodiments, the portion of the reactor vessel 110 between the pre-heat 175 and cool-down 180 zones may include supercritical water during the supercritical water gasification process. Although the pre-heat 175 and cool-down 180 zones are depicted in FIG. 1 as being within the reactor vessel 110, embodiments may provide for the pre-heat and cool-down zones to be located in different components, such as a pre-heater (for the pre-heat zone) and a heat exchanger (for a cool-down zone and/or both the pre-heat zone and the cool-down zone). In addition, the subcritical zones are not limited to the pre-heat 175 and cool-down 180 zones, as any portion of the supercritical water reactor system 100 where the slurry 155 is present in subcritical conditions may include a subcritical zone.

According to some embodiments, the slurry 155 may be more corrosive in subcritical conditions than in supercritical conditions. As such, embodiments provide for a corrosion protection layer (not shown in FIG. 1; see FIGS. 2A, 2B, 3A, and 3B for more detail) configured to provide a barrier between the subcritical water and the components of the supercritical water reactor system 100 within the subcritical zones. The corrosion protection layer may be configured to withstand the thermal expansion that takes place within components of the supercritical water reactor system 100, such as being within the thermal expansion tolerance levels of the component wall material. In addition, the corrosion protection layer may be configured to withstand repeated heating and/or cooling cycles presented by the supercritical water reactor system 100.

The supercritical water reactor system 100 depicted in FIG. 1 is provided for illustrative purposes only and may include more or less components as required, such as one or more valves, pre-heaters, reactor vessels, pumps for pumping the within the slurry 155 through the system and other components known to those having ordinary skill in the art.

FIGS. 2A and 2B depict different views of an illustrative reactor system component comprising a corrosion protection layer according to some embodiments. The reactor system may be a supercritical water reactor system. FIG. 2A depicts a cross-section perpendicular to a longitudinal axis of a reactor system component 200. For example, the component 200 may include a reactor vessel (for example, reactor vessel 110) and FIG. 2A depicts a cross-section through a subcritical zone of the reactor vessel wherein a fluid is present at a subcritical temperature during the supercritical water gasification process (for example, the pre-heat 175 and cool-down 180 sections). As shown in FIG. 2A, a corrosion protection layer 205 may be positioned between the inside surface of the component 200 and the subcritical fluid 210. FIG. 2B depicts a side view of the component 200 with a cut-out, as indicated by the dotted line, showing the corrosion protection layer 205 with the subcritical fluid 210 flowing through the corrosion protection layer. As depicted in FIGS. 2A and 2B, the corrosion protection layer 205 may operate to provide a physical barrier between the subcritical fluid 210 and the inside surface of the component 200, thereby operating to reduce or eliminate corrosion of the component. In an embodiment, the corrosion protection layer 205 may be removed and replaced independently from the component 200 structure.

According to some embodiments, the corrosion protection layer 205 may include glass and silicon carbide (SiC). Under subcritical conditions, silicon carbide does not or substantially does not lose mass due to corrosion or other chemical reactions. Silicon carbide also has a higher thermal conductivity when compared to various reference materials, such as Inconel® of the Special Metals Corporation, Hastelloy® B and Hastelloy® C of Haynes International, Inc, titanium (Ti), and stainless steel. The heat transfer properties of silicon carbide allow the corrosion protection layer 205, among other things, to not interfere or to not significantly interfere with the heat transfer that must occur in various components of the reactor system such as those of the supercritical water reactor system.

In an embodiment, the glass may include borosilicate glass. The borosilicate glass may include at least one of the following: SiO₂, B₂O₃, Na₂O, Al₂O₃, Fe₂O₃, CaO, MgO, and Cl. In an embodiment, the borosilicate glass may be configured as Pyrex® (Corning code 7740) as manufactured by Corning Incorporated, which may include (as percentage of weight) about 80.6% SiO₂, about 12.6% B₂O₃, about 4.2% Na₂O, about 2.2% Al₂O₃, about 0.04% Fe₂O₃, about 0.1% CaO, about 0.05% MgO, and about 0.1% Cl.

Silicon carbide is not conducive to being formed into a layer having a size and shape of components of a reactor system, for example a supercritical water gasification system, such as reactor vessels, heaters, and conduit piping. As such, embodiments provide for a corrosion protection layer formed as a composite material comprising glass as a binding agent that encapsulates the silicon carbide therein. As described in more detail below, embodiments provide for fabricating the composite material by applying silicon carbide crystals to molten glass and allowing the molten glass to solidify to form the corrosion protection layer.

According to some embodiments, the corrosion protection layer may include various ratios of glass and silicon carbide. In an embodiment, the corrosion protection layer may include at least about 20% glass by volume, about 25% glass by volume, about 30% glass by volume, about 40% glass by volume, or in a range between any of these values (including endpoints). In an embodiment, the corrosion protection layer may include at least about 60% silicon carbide by volume, at least about 70% silicon carbide by volume, at least about 80% silicon carbide by volume, or in a range between any of these values (including endpoints). In an embodiment, the corrosion protection layer may include a ratio of glass and silicon carbide such that the corrosion protection layer has a coefficient of expansion the same or substantially the same as silicon carbide alone. Embodiments provide that the corrosion protection layer may include other materials in addition to glass and silicon carbide.

The corrosion protection layer may include silicon carbide crystals of various sizes. FIGS. 3A and 3B depict illustrative corrosion protection layers generated through encapsulation processes using different sizes, or grits, of silicon carbide crystals. In FIG. 3A, a corrosion protection layer 320 resulting from a gross crystal encapsulation process includes a layer of glass 305 with silicon crystals 310 of an appropriate size embedded therein. The size of the silicon crystals 310 may be any size capable of operating according to embodiments described herein and according to any system requirements (for example, heat transfer requirements). In an embodiment, the size for gross crystal encapsulation may include about 5 grit, about 7 grit, about 10 grit, about 12 grit, or in a range between any of these values (including endpoints).

As shown in FIG. 3A, the corrosion protection layer 320 is configured to provide a physical barrier between the inside surface of a subcritical zone of a system component 300 (for example, a heater 105, a reactor vessel 110, a heat exchanger 115, and the like) and the inside area 315 of the component 300, where subcritical fluid may be present during the supercritical water gasification process.

The corrosion protection layer 320 may be made using various processes capable of generating a glass layer 305 encapsulating silicon carbide crystals 310 in a shape and size that may be positioned within a subcritical zone of a system component 300. In an embodiment, the gross crystal encapsulation process may include providing a mold (for example, a drum mold) having the same or substantially the same size and shape as the system component that will house the corrosion protection layer 320. The size and shape of the mold does not necessarily have to be the same size and shape as the system component 300, as long as the resulting corrosion protection layer 320 can be positioned within the system component to provide a physical barrier between the system component and the subcritical fluid. Silicon carbide crystals 310 of an appropriate size (for example, 12 grit) are introduced into the mold, then molten glass (for example, a molten form of the glass layer 305) is poured into the mold. Incrementally, the mold is rotated to generate a layer of molten glass 305 that conforms or substantially conforms to the size and shape of the inner surface of the mold. Before the glass layer 305 is fully hardened, the silicon carbide crystals 310 may be forced into contact with the mold. When the molten glass layer 305 hardens, the silicon carbide crystals 310 may be embedded in the glass layer. According to some embodiments, at least a portion of the silicon carbide crystals 310 may protrude from the surface of the glass layer 305. In this manner, various levels of thermal conductivity may be achieved through the sizing and positioning of the silicon carbide crystals 310.

In FIG. 3B, a corrosion protection layer 325 resulting from a fine crystal encapsulation process includes a layer of glass 305 with silicon carbide crystals 330 of an appropriate size embedded therein. The size of the silicon carbide crystals 330 may be any size capable of operating according to embodiments described herein and according to any system requirements (for example, heat transfer requirements). In an embodiment, the size of the silicon carbide crystals 330 for fine crystal encapsulation may include about 15 grit, about 20 grit, about 30 grit, about 40 grit, or in a range between any of these values (including endpoints). In an embodiment, fine crystal encapsulation may be carried out in a process similar to that described above for gross crystal encapsulation. In another embodiment, fine crystal encapsulation may be carried out by adding the fine silicon carbide crystals 330 into a mold containing the bulk of the molten glass (for example, a molten form of the glass layer 305), in a process similar or substantially similar to vitrification.

FIG. 4 depicts a flow diagram for an illustrative corrosion reduction method for a reactor system according to some embodiments. A system vessel may be provided 405 within a reactor system such as a supercritical water reactor system. An illustrative system vessel is the supercritical water reactor system 100 depicted in FIG. 1. The system vessel may include any reactor system component, such as that of a supercritical water reactor system, having a subcritical zone, for example, a region in contact with subcritical fluid during the supercritical water reactor process that is susceptible to corrosion by corrosive ions in the subcritical fluid. Non-limiting examples of components include reactor vessels, heaters, pre-heaters, heat exchangers, conduit, and piping.

A corrosion protection layer may be provided 410 that includes glass and silicon carbide. The corrosion protection layer may be produced according to any method capable of fabricating a corrosion protection layer configured according to embodiments described herein. Illustrative and non-restrictive fabrication processes include gross crystal encapsulation, fine crystal encapsulation, and filament winding as described in relation to FIGS. 3A, 3B and 5, respectively. The corrosion protection layer may be positioned within the subcritical zone of the system vessel such that it is stationary and does not move from the subcritical zone using various methods and/or elements, including, without limitation, fasteners, anchors, adhesives, clamps, and/or sizing the corrosion protection layer such that it may be immovably embedded in the subcritical zone (for example, through a tight fit between the corrosion protection layer and the subcritical zone).

The reactor vessel may be configured 415 such that subcritical fluid is received within a subcritical zone of the system vessel. For example, all or substantially all of the reactor vessel may include a subcritical zone, such as a pipe wherein subcritical fluid passes through on its way to another component. In another example, a system vessel may include multiple zones, with one or more zones being subcritical zones and one or more other zones being non-subcritical zones (for example, a supercritical zone, a zone where the temperature of the fluid is below subcritical temperatures, or the like). As shown in FIG. 1, a reactor vessel 110 may include pre-heat 175 and cool-down 180 zones where subcritical fluid is present during the supercritical water gasification process.

The corrosion protection layer may operate to provide 420 a physical barrier between the fluid and an inner surface of the system vessel within the subcritical zone. As described above, the inner surface of the system vessel may be susceptible to corrosion from the corrosive ions present in the subcritical fluid. The corrosion protection layer may reduce or eliminate contact between the corrosive ions present within the subcritical fluid and components of the reactor system, such as a supercritical water gasification system. Corrosion of protected system components is thereby reduced because the corrosive ions cannot contact and react with surfaces protected by the corrosion protection layer to cause corrosion.

FIG. 5 depicts a flow diagram for an illustrative method of providing a corrosion protection layer using a filament winding process according to some embodiments. A system vessel may be provided 505 within a reactor system, such as a supercritical water reactor system. The system vessel may include any reactor system component having a subcritical zone. A mold may be provided 510 that has a size and shape that substantially conforms to the size and shape of the inside of the system vessel within a subcritical zone. In this manner, a corrosion protection layer fabricated using the mold may fit within the system vessel.

The mold may be rotated 515 and silicon carbide fibers may be applied 520 to the outside of the rotating mold under tension. In an embodiment, application 520 of the silicon carbide fibers may follow or substantially follow a filament winding process as known to those having ordinary skill in the art. For example, the tension of the silicon carbide fibers may be carefully controlled such that higher tension may generate a corrosion protection layer with high rigidity and strength and lower tension may provide a corrosion protection layer with more flexibility. In another example, the orientation of the filaments may be such that successive layers are orientated differently from previous layers to affect the strength of the corrosion protection layer. For instance, a high angle “hoop” pattern may provide “crush” strength, while a lower angle “closed” or “helical” pattern may provide greater tensile strength. In an embodiment, the tension of the silicon carbide fibers resulting from filament winding may be about 0.2 kilopascals, about 0.5 kilopascals, about 1.0 kilopascals, about 1.5 kilopascals, about 2.0 kilopascals, about 2.5 kilopascals, about 3 kilopascals, about 5 kilopascals, and ranges between any two of these values (including endpoints).

A corrosion protection layer may be formed 525 by impregnating the silicon carbide fibers with molten glass during application of the silicon carbide fibers to the mold. In certain filament winding processes, fibers applied to a mold are impregnated with resin and the completed layer may be about 60% fiber by volume to about 80% fiber by volume. Some embodiments provided herein use molten glass (for example, borosilicate glass, Pyrex®, or the like) as the resin. In an embodiment, a heating element, such as a blowtorch, may be used to heat the glass when impregnating the silicon carbide fibers to maintain the glass in a molten state. According to some embodiments, the corrosion protection layer formed 525 by the filament winding process may include about 60% fiber by volume, about 70% fiber by volume, about 80% fiber by volume, or ranges in between any two of these values (including endpoints), with all or substantially all of the remaining portion being formed from the glass. Forming 525 the corrosion protection layer through filament winding has various advantages, including, among other things, significant structural strength compared with other fabrication processes.

The corrosion protection layer may be solidified 530 responsive to the filament winding process producing a corrosion protection layer that substantially conforms to the size and shape of the inside of the system vessel such that the corrosion protection layer fits therein. In general, the corrosion protection layer may be solidified 530 by stopping the filament winding process and allowing the corrosion protection layer to cool. The corrosion protection layer substantially conforms to the size and shape of the inside of the system vessel when it reaches a size and shape such that it may be positioned 535 within the subcritical zone of the system vessel according to the particular installation method. According to some embodiments, the corrosion protection layer may be immovably positioned 535 within the subcritical zone using various methods, such as fasteners, adhesives, and/or sizing the corrosion protection layer such that it will not move once positioned within the subcritical zone.

EXAMPLES Example 1 Supercritical Water Biomass Gasification System

A supercritical water reactor system will be configured to generate a synthesis gas including H₂, CO₂, CH₄, and CO from biomass feedstock. The biomass feedstock will include organic wastes that provide cellulose, hemicellulose and lignin compounds, such as wood sawdust, rice straw, rice shells, wheat stalks, peanut shells, corn stalks, corn cobs, and sorghum stalk.

The biomass feedstock will be in the form of an aqueous liquid biomass slurry that will react with supercritical water in a reactor vessel of the supercritical water reactor system to generate the synthesis gas. The biomass feedstock will be introduced into the system and will be heated in a preheater and a heater before entering the reactor vessel. The preheater will heat water within the biomass feedstock to a subcritical temperature of about 620 Kelvin at a pressure of about 22.1 megapascals. The biomass feedstock will flow through a heat exchanger before entering the heater. Accordingly, the preheater and the heat exchanger will include a first subcritical zone of the supercritical water reactor system. The subcritical water will include corrosive ions, such as the ions of various inorganic salts such as NaCl. The subcritical water will flow to the heater through a conduit where it will be heated to a supercritical temperature of about 920 Kelvin at a pressure of about 22.1 megapascals before flowing into the reactor vessel. The conduit will be a second subcritical zone of the supercritical water reactor system. The preheater and the conduit will be fabricated from stainless steel.

A first corrosion protection layer will be positioned within the first subcritical zone of the preheater and the heat exchanger. The first corrosion protection layer will include about 70% silicon carbide crystals by volume encapsulated within about 30% Pyrex® by volume through a gross crystal encapsulation process. The silicon carbide crystals will have a size of about 10 grit. The larger silicon carbide crystals of the first corrosion protection layer will provide a high level of heat transfer within the preheater.

A second corrosion protection layer will be positioned within the second subcritical zone of the conduit. The second corrosion protection layer will include about 60% silicon carbide crystals by volume encapsulated within about 40% Pyrex® by volume through a fine crystal encapsulation process. The silicon carbide crystals will have a size of about 30 grit. The smaller silicon carbide crystals of the second corrosion protection layer and the larger percentage of glass will provide a lower level of heat transfer within the conduit as compared with the first corrosion protection layer.

The first and second corrosion protection layers will provide a physical barrier that reduces or eliminates the corrosive ions from contacting the stainless steel inner surfaces of the preheater, the heat exchanger and the conduit. Accordingly, the corrosive ions cannot react with and cause corrosion of the inner surface of the preheater, the heat exchanger and the conduit, prolonging the life of these components within the supercritical water reactor system relative to a similar system lacking the corrosion protection layers.

Example 2 Supercritical Water Reactor System Reactor Vessel with Subcritical and Supercritical Zones

A supercritical water coal gasification system will include a cylindrical reactor vessel having a length of about four meters and a diameter of about two meters. A pump will pump a coal slurry at a subcritical temperature of about 600 Kelvin at a pressure of about 23 megapascals from a heater through a first opening of the reactor vessel. The coal slurry will be heated within the reactor vessel to a supercritical temperature of about 875 Kelvin at a pressure of about 25 megapascals. The supercritical water within the coal slurry will react with components of the coal slurry within the reactor vessel and the resulting product will flow out of the reactor vessel through a second opening. The reactor vessel will be fabricated from Hastelloy® C-22.

Subcritical water will be present within the coal slurry in the reactor vessel in a first subcritical zone extending for about one meter from the first opening, in a heat-up zone. Supercritical water will be present within the coal slurry in a supercritical zone in the reactor vessel extending from the end of the first subcritical zone opposite the first opening to about one-half meter from the second opening. A second subcritical zone will extend from the second opening to about one-half meter inside the reactor vessel, within a cool-down zone.

Two corrosion protection layers will be fabricated, one for each subcritical zone, through a filament winding process. A mold will be used for winding the silicon carbide filaments impregnated with molten glass. The molten glass will include SiO₂, B₂O₃, Na₂O, Al₂O₃, Fe₂O₃, CaO, MgO, and Cl. A first corrosion protection layer and a second corrosion protection layer will be fabricated using filament winding on the mold having a length of about one meter and about one-half meter, respectively. Each of the first corrosion protection layer and the second corrosion protection layer will have a diameter such that they may be immovably positioned within the reactor vessel due to a tight fit between the inside surface of the reactor vessel and the outside surface of each corrosion protection layer. The first corrosion protection layer will include about 80% silicon carbide by volume and about 20% glass by volume to facilitate heat transfer. The second corrosion layer will include about 60% silicon carbide by volume and about 40% glass by volume to provide a heat transfer rate less than the first corrosion protection layer.

The first corrosion protection layer and the second corrosion protection layer will be positioned within the reactor vessel. The reactor vessel will be sealed and connected within the supercritical water coal gasification system. The first corrosion protection layer and the second corrosion protection layer will provide a physical barrier reducing contact between the subcritical fluid in the first subcritical zone and the second subcritical zone and the inner surface of the reactor vessel, thereby reducing corrosion of the reactor vessel during the supercritical water coal gasification process relative to a similar system lacking the corrosion protection layers.

In the above detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be used, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (for example, bodies of the appended claims) are generally intended as “open” terms (for example, the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to”). While various compositions, methods, and devices are described in terms of “comprising” various components or steps (interpreted as meaning “including, but not limited to”), the compositions, methods, and devices can also “consist essentially of” or “consist of” the various components and steps, and such terminology should be interpreted as defining essentially closed-member groups. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (for example, “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (for example), the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, et cetera” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (for example, “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, et cetera). In those instances where a convention analogous to “at least one of A, B, or C, et cetera” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (for example, “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, et cetera). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, or the like. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, a middle third, and an upper third. As will also be understood by one skilled in the art all language such as “up to,” “at least,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments. 

1. A reactor system configured to reduce or eliminate corrosion thereof, the system comprising: a system vessel comprising an inner surface, and having a subcritical zone configured to receive fluid at subcritical conditions; and at least one corrosion protection layer comprising silicon carbide at least partially encapsulated in glass, the at least one corrosion protection layer being positioned within the subcritical zone to provide a physical barrier that protects at least a portion of the inner surface from corrosion by the fluid.
 2. The system of claim 1, wherein the reactor system is a supercritical water reactor system.
 3. (canceled)
 4. The system of claim 1, further comprising a pump configured to pump the fluid through the system vessel. 5.-6. (canceled)
 7. The system of claim 1, further comprising a pre-heater.
 8. The system of claim 1, further comprising a heat exchanger.
 9. The system of claim 1, wherein the system vessel is configured as one of a reactor vessel, a pre-heater, and a heat exchanger.
 10. The system of claim 1, wherein the reactor system is configured as a supercritical coal water gasifier. 11.-13. (canceled)
 14. The system of claim 1, wherein water within the subcritical zone is configured to a temperature below about 647 Kelvin.
 15. The system of claim 1, wherein water within the subcritical zone is configured to a temperature between about 570 Kelvin and about 647 Kelvin.
 16. The system of claim 1, wherein water within the subcritical zone is configured to a pressure of about 25 MPa.
 17. (canceled)
 18. The system of claim 1, wherein the glass comprises borosilicate glass.
 19. The system of claim 18, wherein the borosilicate glass comprises at least one of the following: SiO₂, B₂O₃, Na₂O, Al₂O₃, Fe₂O₃, CaO, MgO, and Cl.
 20. (canceled)
 21. The system of claim 18, wherein the borosilicate glass comprises about 80.6% SiO₂ by weight, about 12.6% B₂O₃ by weight, about 4.2% Na₂O by weight, about 2.2% Al₂O₃ by weight, about 0.04% Fe₂O₃ by weight, about 0.1% CaO by weight, about 0.05% MgO by weight, and about 0.1% Cl by weight.
 22. (canceled)
 23. The system of claim 1, wherein the at least one corrosion protection layer comprises less than about 40% glass by volume.
 24. The system of claim 1, wherein the at least one corrosion protection layer comprises at least about 20% glass by volume.
 25. (canceled)
 26. The system of claim 1, wherein the at least one corrosion protection layer comprises at least about 60% silicon carbide by volume.
 27. The system of claim 1, wherein the at least one corrosion protection layer comprises about 60% silicon carbide by volume to about 80% silicon carbide by volume. 28.-71. (canceled)
 72. A method for reducing or eliminating corrosion in a reactor system, the method comprising: providing a reactor system having a system vessel, the system vessel comprising an inner surface and having a subcritical zone configured to receive fluid at subcritical conditions; providing at least one corrosion protection layer comprising silicon carbide at least partially encapsulated by glass; and positioning the at least one corrosion protection layer within the subcritical zone to provide a physical barrier that protects at least a portion of the inner surface from corrosion by the fluid at subcritical conditions.
 73. (canceled)
 74. The method of claim 72, wherein providing the reactor system comprises providing a supercritical water reactor system. 75.-78. (canceled)
 79. The method of claim 72, further comprising a pump configured to move the fluid through the system vessel.
 80. The method of claim 72, wherein receiving the fluid at subcritical conditions comprises receiving the fluid at a subcritical temperature less than about 647 Kelvin.
 81. (canceled)
 82. The method of claim 72, wherein receiving the fluid at subcritical conditions comprises receiving the fluid at a subcritical pressure of about 25 MPa.
 83. The method of claim 72, wherein receiving the fluid at subcritical conditions comprises receiving the fluid at a subcritical temperature of about 620 Kelvin and a subcritical pressure of about 25 MPa.
 84. (canceled) 